Fleet depot charging should start with the next departure, not the largest charger in a catalogue. The useful question is how much energy each vehicle needs before it leaves, and how long the depot has to supply it. Once those two inputs are understood, the operator can choose charging equipment and a power schedule that fit the working day.

A delivery van parked overnight has a different charging requirement from a taxi returning for a short break. Even vehicles with identical batteries can need different charging arrangements if their routes, parking windows or reserve policies differ. Buying the same charger for every bay can therefore create unnecessary cost in one part of the depot and a bottleneck in another.

Build a vehicle schedule before an equipment list

For each vehicle group, record its usual return time, earliest departure, daily distance and energy consumption. Include time spent unloading, cleaning or waiting for a parking space. A vehicle that reaches the depot at 7 p.m. may not be available to charge until 8 p.m.

Use vehicle data or measured route records where available. Battery capacity alone does not show the energy that must be replenished each night. A vehicle with a large battery may return with substantial charge remaining, while a smaller vehicle working two shifts may need an additional daytime session.

Separate routine days from demanding days. Cold weather, heavier payloads, route extensions and heating or cooling can change energy use. The charging plan should explain which conditions it is designed to cover and what happens when a vehicle falls outside that operating envelope.

Translate daily energy into a power requirement

Consider an illustrative depot with 20 vans, each needing 30 kWh added to its battery during an eight-hour charging window. The batteries need 600 kWh in total. If charging from the site meter to the batteries is assumed to be 90 percent efficient, the corresponding grid energy is about 667 kWh. Spread evenly across eight hours, that represents an average charging input of about 83 kW.

This is a planning estimate, not a recommended electrical service rating. It assumes all vehicles are connected throughout the window and that their charging behaviour allows the energy to be distributed as planned. Late arrivals, charging taper, auxiliary loads and individual vehicle limits can require a different schedule or additional capacity.

The calculation is useful because it separates the energy task from the sum of charger nameplate ratings. Installing 20 charging points does not necessarily mean that every point must draw its maximum power at once. It does mean that the control system and electrical design must safely manage the actual simultaneous demand.

Prioritize departures rather than charging everything equally

A schedule should allocate power according to departure deadlines and energy deficits. Giving every connected vehicle an equal share can be inefficient when some leave at 5 a.m. and others remain until lunchtime.

Priority rules need an owner. Dispatch may change a route after the charging schedule has been created, so the depot needs a practical way to update the required departure time or target charge. If the software does not receive vehicle battery information, the operator must establish how it will estimate or enter the energy requirement instead.

When comparing supplier approaches, the EVB fleet charging overview provides a starting point for discussing AC and DC equipment, charging schedules and available site capacity. A useful quotation should turn that overview into a site-specific equipment list and a clearly defined control arrangement.

Test the schedule against a difficult working day

Before purchase, replay a demanding day. Include the last vehicle to return, the first vehicle to leave and the largest energy requirement. Then remove one charging point from service and check which departures are affected.

This exercise can reveal whether the depot needs a spare bay, a limited amount of faster charging or a different parking arrangement. It can also show that additional charger power will not solve the problem if the site cannot supply more electricity during the relevant period.

The facility load must be included. Refrigeration, workshops or building services may still consume power while vehicles charge. The charging budget should be based on assessed available capacity, not simply the main connection rating minus a rough estimate.

Define the acceptance test in operational terms

Commissioning should demonstrate that representative vehicles receive their required energy before departure while the site remains within its approved electrical limits. Test a late arrival, a changed departure priority and a communication interruption, as well as a normal charging session.

Record who receives an alert and who can intervene when a vehicle is unlikely to be ready. A dashboard that reports a problem after the morning shift has left provides little operational protection.

The result should be a repeatable overnight process: drivers know where to park and connect, dispatch knows how to change priorities, and the duty manager can identify an unfinished charging task early enough to act. That is a more useful purchasing objective than maximum charging power alone.